341–350 of 451 posts
A very jovial discussion of systems that have killed millions of innocent people. Maybe you could do the same treatment of Nazi gas chambers or something for the next video?
Earlier quoted context omitted.
For C, the proper/expected/standard way to reference a variable without accessing it is a cast to void: (void) a; I'm sure there are commonly-implemented compiler extensions, but this is the normal/native way and should always work.
Not if you use GCC. https://godbolt.org/z/zYdc9ej88 clang gets this right.
and assigning to std::ignore works for both.
Earlier quoted context omitted.
I've always strongly disliked this argument of not enough X programmers. If the DoD enforces the requirement for Ada, Universities, job training centers, and companies will follow. People can learn new languages. And the F35 and America's combat readiness would be in a better place today with Ada instead of C++.
The exact opposite of what you suggest already happened: Ada was mandated and then the mandate was revoked. It’s generally a bad idea to be the only customer of a specific product, because it increases costs. > And the F35 and America's combat readiness would be in a better place today with Ada instead of C++ What’s the problem with the F35 and combat readiness? Many EU countries are falling over each-other to buy it…
For example, the UK would like to use its own air-to-ground missile (the spear missile) with its own F-35 jets, but it's held back by Lockheed Martin's Block 4 software update delays.
Earlier quoted context omitted.
Your points are correct, but recursion is banned anyway in safety critical applications. The main issue is determinism. The fact you have to use the stack for call stacks is correct OP seems misinformed.
You have to use the stack for procedure calls on x86/x86-64 CPUs, where the hardware enforces this. In most other surviving CPU ISAs the return address is saved in a register and it is easy to arrange in a compiler to use only procedure arguments that are passed in registers, the only price being paid for this being a reasonable upper limit for the number of parameters of a function, e.g. 12 or 24, depending on the n…
What do you get by doing it like this?
Also, in your described structure, how do you handle nested function calls? I'm sure there exists a convoluted scheme that does this, but not sure with the current call assumptions.
You also lose ABI compatibility with a bunch of stuff.
And regardless, I mostly program in Risc-v and ARM -most compiles like to pass arguments on the registers, but use the stack anyway for local context.
Earlier quoted context omitted.
You have to use the stack for procedure calls on x86/x86-64 CPUs, where the hardware enforces this. In most other surviving CPU ISAs the return address is saved in a register and it is easy to arrange in a compiler to use only procedure arguments that are passed in registers, the only price being paid for this being a reasonable upper limit for the number of parameters of a function, e.g. 12 or 24, depending on the n…
I believe it's possible to do what you've described, but I am not aware of any compiler that does this. What do you get by doing it like this? Also, in your described structure, how do you handle nested function calls? I'm sure there exists a convoluted scheme that does this, but not sure with the current call assumptions. You also lose ABI compatibility with a bunch of stuff. And regardless, I mostly program in Risc…
I don't think it's too hard to imagine a compiler that does that, although it would obviously be very limited in functionality (nesting would be disallowed as you note, or I guess limited to the number of registers you're willing to waste on it...).
TL;DR - no exceptions - no recursion - no malloc()/free() in the inner-loop
Forbidding recursion is pretty annoying. One of the nice things that's on the distant horizon for Rust is an explicit tail recursion operator perhaps named `become`. Unlike naive recursion, which as this video (I haven't followed the link but I'm assuming it is Laurie's recent video) explains risks stack overflow, optimized tail recursion doesn't grow the stack. The idea of `become` is to signal "I believe this can b…
Earlier quoted context omitted.
I like rust matching for this reason: You need to cover all branches. In fact, not using a default (the else clause equivalent) is ideal if you can explicitly cover all cases, because then if the possibilities expand (say a new value in an enum) you’ll be annoyed by the compiler to cover the new case, which might otherwise slip by.
And I like using enums in C ;-) The compiler tells you to cover all branches. https://godbolt.org/z/bY1P9Kx7n
fn g(x: u8) { match x { 0..=10 => {}, 20..=200 => {},
}That for example would complain about the ranges 11 to 19 and 201 to 255 not being covered.
You could try to map ranges to enum values, but then nobody would guarantee that you covered the whole range while mapping to enums so you’d be moving the problem to a different location.
Rust approach is not flawless, larger data types like i32 or floats can’t check full coverage (I suppose for performance reasons) but still quite useful.
Earlier quoted context omitted.
I went through the TS positive vetting process (for signals intelligence, not writing software for fighter jets, but the process is presumably the same). If I were back on the job market, I’d be demanding a big premium to go through it again. It’s very intrusive, puts significant limitations on where you can go, and adds significant job uncertainty (since your job is now tied to your clearance).
Yes but like a certification, that clearance is yours, not the companies. You take it with you. It lasts a good while. There are plenty of government companies that would love you if you had one. Northrop, Lockheed, Boeing, etc.
https://web.archive.org/web/20111219004314/http://journal.th... (referenced, at least tangentially, in the video) is a piece from the engineering lead which does a great job discussing Why C++. The short summary is "they couldn't find enough people to write Ada, and even if they could, they also couldn't find enough Ada middleware and toolchain." I actually think Ada would be an easier sell today than it was back the…
I've always strongly disliked this argument of not enough X programmers. If the DoD enforces the requirement for Ada, Universities, job training centers, and companies will follow. People can learn new languages. And the F35 and America's combat readiness would be in a better place today with Ada instead of C++.
But, not because I think schools and colleges would jump at the opportunity and start training the next batch of students in said language just because some government department or a bunch of large corporations supported and/or mandated it. Mostly because that hasn't actually panned out in reality for as long as I can remember. Trust me, I _wish_ schools and colleges were that proactive or even in touch with with the industry needs, but... (shrug!)
Like I said, I still think the original argument is flawed, at least in the general case, because any good organization shouldn't be hiring "language X" programmers, they should be hiring good programmers who show the ability to transfer their problem solving skills across the panopticon of languages out there. Investing in getting a _good_ programmer upskilled on a new language is not as expensive as most organizations make it out to be.
Now, if you go and pick some _really obscure_ (read "screwed up") programming language, there's not much out there that can help you either way, so... (shrug!)
Earlier quoted context omitted.
I've always strongly disliked this argument of not enough X programmers. If the DoD enforces the requirement for Ada, Universities, job training centers, and companies will follow. People can learn new languages. And the F35 and America's combat readiness would be in a better place today with Ada instead of C++.
The exact opposite of what you suggest already happened: Ada was mandated and then the mandate was revoked. It’s generally a bad idea to be the only customer of a specific product, because it increases costs. > And the F35 and America's combat readiness would be in a better place today with Ada instead of C++ What’s the problem with the F35 and combat readiness? Many EU countries are falling over each-other to buy it…